Last x Days Posts  1 | 3 | 7 Days  Search  Topics  Tree View  Help
  Soarer Central * General Soarer Chat * Some intercooler theory, any comments? Previous Previous    Next Next  

Author Message
Cihan Aday
DieHard
Victoria
JZZ30

Posts: 556
Reg: 07-2005

Top of pagePrevious messageNext messageBottom of page Link to this message

Rating: N/A
Votes: 0 (Vote!)

Tuesday, February 21, 2006 - 11:49 pm, by:  Cihan Aday (Cihan) Quote hilighted text Edit Post Delete Post Print Post   View Post/Check IP (Moderator/Admin Only) Move Post (Moderator/Admin Only)

Something i wrote on another forum;

".....if you have a working wastegate actuator, the turbo will be forced to spin faster to compensate for the pressure drop caused by the intercooler and the cooling of the intake charge anyway!

I dont see why high school physics has to be reverted to when there are industry based ways to talk about things such as pressure drop.

Pressure drop 'across' x = Flow reduction at set temperature 'across' x

A reduction of air pressure due to the dissipation of heat is just that, nothing more. A cheap crappy restrictive intercooler will make the turbo work harder to produce the same boost at the intake manifold, and could potentially increase initial turbo outlet charge temperatures to the point where the resulting pressure and temperature of the air leaving the intercooler is exactly the same as the standard item its replacing.

Ideally you want an intercooler that flows well (low pressure drop across intercooler), and inflicts the largest possible drop in air temperature (pressure drop because of temperature reduction). In this case, the engine would make more power than it did before. This time though, with lower boost (as measured at intake manifold). This is because the restriction or pressure drop across the standard cooler has been removed. If the reduction in restriction is 3psi, you will gain the equiv. of increasing boost pressure by 3psi (without considering compressor efficiency). The turbo wont actually spin any faster than it was before. The cooling effect of an intercooler (pressure drop because of temperature reduction) only allows you to generate more ponies if you actually increase boost pressure at the intake (hence how fast the turbo spins!).

Put simply, the only way to increase power without making the turbocharger work any harder is to remove restrictions; both before and after the compressor intake, and after the turbine exhaust. If we also start involving temperatures before the compressor (ie. intake temperature), we can develop the following extremely basic (but applicable) theory;

The only way to make more power without making the turbo work any harder is to remove restrictions and reduce air temperatures at the compressor intake and remove restrictions after the compressor and exhaust turbine outlets.
Looking at it simply; having an intercooler that reduces air temperatures is not increasing the amount of oxygen in the system (more oxygen is required to support further combustion and generate additional power). Unless; A. the turbo spins faster to compensate for the pressure loss caused by reduction in intake temperature, or B. The intake temperature at the compressor intake is reduced (so for a given compressor revolution, more oxygen is added to the induction system.)

In conclusion, you cant get more power by fitting an intercooler that flows as well as whatever was there originally, without increasing boost pressure. The idea behind big intercoolers is temperature reduction for safe power generation and engine longetivity. Ignition can be advanced, less thermally conductive sparkplugs can be used (lower heatranges, for drivability reasons) and lower octane fuel can be used while maintaining the same power level.


Anyone have any objections or corrections?

Bar the spelling mistakes, is it worth posting in the article section for those interested?
Im aware that its not complete, but you could go on for ever explaining everything from scratch.
As long as it makes sense ill add to it :-)

Cheers,
Cihan.
Michael Sztyk
Tinkerer
Victoria
1JZ-GTE Soarer TT

Posts: 15
Reg: 12-2005

Top of pagePrevious messageNext messageBottom of page Link to this message

Rating: N/A
Votes: 0 (Vote!)

Wednesday, February 22, 2006 - 04:08 am, by:  Michael Sztyk (Sli1) Quote hilighted text Edit Post Delete Post Print Post   View Post/Check IP (Moderator/Admin Only) Move Post (Moderator/Admin Only)

WOW hehe...
while on the subject of coolers...
im fitting my cooler tomorrow, getting the piping done the next day and doing the intake too. thats 2 more bottle necks im removing. couple of weeks ago just fitted a 3" exhaust from the turbo back so im sure that will make the diff too as im able to flow more through there now.
Has become much more responsive since the exhaust has been done.
Just wondering on your opinions with the intake i was thinking of.
Basically, when the front mount gets done ill have no use for the factory cooler and that will go (weight reduction LOL), instead i was thinking of putting a K&N cone in place of the factory cooler and using the cooler piping running up through the guard and using that as an intake pipe. That way i could achieve forced cool air intake.
But my question on the other hand is, is there a certain length of intake piping that should be maintained or would i be taking the filter too far away from where it should be? Hope that makes sense to you...
What im trying to achieve there is no hot engine bay air at all going into the air intake.

Opinions would greatly be appreciated.
Ive only had my ride for a year but its becoming addictive slowly doing it up LOL
Cool $hite
Chris Davey
TryHard
QLD
Corona

Posts: 414
Reg: 07-2005

Top of pagePrevious messageNext messageBottom of page Link to this message

Rating: N/A
Votes: 0 (Vote!)

Wednesday, February 22, 2006 - 10:50 am, by:  Chris Davey (Chris_davey) Quote hilighted text Edit Post Delete Post Print Post   View Post/Check IP (Moderator/Admin Only) Move Post (Moderator/Admin Only)

Cihan: looks good :-) Maybe mention also about piping size being too large. ie. use larger piping to reduce the restrictions but then have additional lag because of the extra volume. Also maybe something about bottle necks in the system like using the same size piping for outlets, inlets and throttle body.
Anton Jones
Tinkerer
QLD
JZZ30

Posts: 66
Reg: 08-2005

Top of pagePrevious messageNext messageBottom of page Link to this message

Rating: N/A
Votes: 0 (Vote!)

Wednesday, February 22, 2006 - 11:34 am, by:  Anton Jones (Alj) Quote hilighted text Edit Post Delete Post Print Post   View Post/Check IP (Moderator/Admin Only) Move Post (Moderator/Admin Only)

Michael,

I wouldn't fit the filter down there, it will 'pickup' water when it rains.. not a good thing mate. If you go through a pool of water one day your turbo will get a mouthful!

Have forced air from down there for sure just make sure the water can get away some how (ie two/tree small holes in the tubing).
Michael Sztyk
Tinkerer
Victoria
1JZ-GTE Soarer TT

Posts: 17
Reg: 12-2005

Top of pagePrevious messageNext messageBottom of page Link to this message

Rating: N/A
Votes: 0 (Vote!)

Thursday, February 23, 2006 - 08:37 am, by:  Michael Sztyk (Sli1) Quote hilighted text Edit Post Delete Post Print Post   View Post/Check IP (Moderator/Admin Only) Move Post (Moderator/Admin Only)

Good point Anton...
Should be able to think of something

Add Your Message Here
Eye Candy
Click for full size
Bold text Italics Underline Center Text Upload photo from your hard drive Make a List Make a Table Make an Image Thumbnail Create a hyperlink Insert a clipart image Formatting Help
         

Username: Important Posting Information:
If asking a question, have you done a search to see if your question has already been answered?
Be aware that the use of SMS-speak eg "u" instead of "you" etc, will get your post deleted.
Password:
Enable HTML code in message
Automatically activate URLs in message

  Administration Administration      Log Out Log Out Previous Previous      Next Next